1. Field of the Invention
The present invention relates to a light source apparatus having an illumination unit and an adapter unit that is attachable to/detachable from this illumination unit.
2. Description of the Related Art
For example, Japanese Patent No. 4370199 discloses an endoscope apparatus. This endoscope apparatus has, e.g., a light source unit that emits light having a specific wavelength and an inserting section that guides the light emitted from the light source unit. Further, this endoscope apparatus also has a diffusion optical member that is arranged at a distal end portion of the inserting section that is an optical illumination unit and diffuses and emits light frontward, and an adapter unit that is attachable to/detachable from the distal end portion of the inserting section.
The light source unit has a light source section that emits light having a specific wavelength, e.g., 450 nm or less and a light focusing member that focuses the light emitted from the light source section. The light source section has, e.g., laser diodes that emit laser beams that are excitation lights.
The inserting section has a light guide that guides the light to the distal end portion of the inserting section. This light is emitted from a laser light source and focused by the light focusing member. The light guide is formed of, e.g., an optical fiber. The light guide has an emit end portion arranged at the distal end portion of the inserting section.
The diffusion optical member is arranged at the distal end portion of the inserting section to face the emit end portion of the light guide. The diffusion optical member has, e.g., a diffusion lens. The distal end portion of the inserting section including the diffusion optical member is included in the optical illumination unit.
The adapter unit is attached to the distal end portion of the inserting section to cover a front face of the distal end portion of the inserting section. The adapter unit holds a discoid fluorescent substance that emits light having a wavelength different from a wavelength of the light emitted from the light source section based on this light. The fluorescent substance is a wavelength conversion member and also an optical member.
The adapter unit has a front face plate arranged on a front face of the adapter unit. The front face plate has an illumination window that faces the diffusion optical member and the fluorescent substance arranged in the entire illumination window. Furthermore, the front face plate has a cylindrical reflection member that is a mirror surface that is arranged on an entire inner peripheral surface of the illumination window and on the diffusion optical member side to the fluorescent substance. The reflection member is a diffusion prevention member that prevents diffusion of light. An inner diameter of the reflection member is substantially equal to an outer diameter of the diffusion optical member or larger than the outer diameter of the diffusion optical member.
When the fluorescent substance is irradiated with a laser beam, it emits light including light of a wavelength of substantially 400 nm to substantially 650 nm frontward. This light is, e.g., white light.
In the endoscope apparatus, the adapter unit having the fluorescent substance is attachable to/detachable from the distal end portion of the inserting section in the optical illumination unit. Therefore, emission of the light of 450 nm or less and emission of the white light are easily changed over by attachment/detachment of the adapter unit. In other words, when the adapter unit is detached, the light emitted from the light source section is diffused by the diffusion optical member and allowed to emit as diffusion light. Furthermore, when the adapter unit is attached, substantially all of the diffused light is focused to the fluorescent substance by the reflection member and transmitted through the fluorescent substance. At this time, the diffused light is turned to the white light and allowed to emit by the fluorescent substance.
As described above, in Japanese Patent No. 4370199, substantially all of the diffused light is guided to the fluorescent substance by the reflection member. However, Japanese Patent No. 4370199 does not disclose a configuration for a light guide. Specifically, a beam divergence angle of the diffused light emitting from the diffusion optical member and an optical connection configuration of the diffusion optical member and the reflection member are not disclosed.
Therefore, there is a concern that the light is not efficiently guided from the optical illumination unit to the adapter unit.
In view of the above-described circumstances, it is an object of the present invention to provide a light source apparatus that can efficiently guide light from an optical illumination unit to an adapter unit.